[hooande]

Can I ask why you're charging for this at all? The cost to you has to be close to negligible. Even with expensive hosting, I would be surprised if you had to pay more than $200/mo at the height of popularity.

You might want to look into sponsorship. No need for banner ads, just create one or two "sponsored by" slots or messages. Give them away at first to your friends or companies you like at first. If the site becomes popular enough that hosting costs are an issue, there will be people willing to pay to get their name out there (office products, other office related software).

A lot of people, especially at 37Signals, have this "If you're not charging money for your software, you're a sucker" attitude. That can be true, but it's certainly not the only advice for every situation. A lot of people have trouble differentiating between "growing business" and "cool thing that I made". Unless you have some kind of hidden costs, you might get much more traction by just putting this out there.